The Dynamical Characteristics of a Disappearing-Filament Associated Interplanetary Disturbance Observed in 1992 Early May

Abstract

Abstract The dynamical properties of an interplanetary disturbance related to the sudden commencement of a geomagnetic storm at 15h41m UT on 1992 May 9 are discussed based on solar-wind data obtained by the interplanetary scintillation technique and soft X-ray images taken with the Soft X-ray Telescope on board Yohkoh. It is suggested here that the sudden commencement was associated with the disappearance of a quiescent filament, which took place in the south-east quadrant of the solar disk at about 07h UT on 1992 May 7. An associated shock wave propagated at approximately a constant speed of about 1000 km s–1 up to about 0.3 AU from the Sun, then showed a blast-wave like deceleration. If this was the case, the duration of the “driven-like phase” of the shock was about 12 hr. According to Yohkoh soft X-ray images, a transient coronal hole was formed near to the disappearing filament. The lifetime of this coronal hole, about 17 hr, was comparable to the duration of the driven phase of the shock wave. A close connection between the dynamical characteristics of the shock wave and the formation of the transient coronal hole is suggested.